Development of a Chemically Defined Medium for Better Yield and Purification of Enterocin Y31 from Enterococcus faecium

The macro- and micronutrients in traditional medium, such as MRS, used for cultivating lactic acid bacteria, especially for bacteriocin production, have not been defined, preventing the quantitative monitoring of metabolic flux during bacteriocin biosynthesis. To enhance Enterocin Y31 production and simplify steps of separation and purification, we developed a simplified chemically defined medium (SDM) for the growth of Enterococcus faecium Y31 and production of its bacteriocin, Enterocin Y31. We found that the bacterial growth was unrelated to Enterocin Y31 production in MRS; therefore, both the growth rate and the Enterocin Y31 production were set as the index for investigation. Single omission experiments revealed that 5 g/L NaCl, five vitamins, two nucleic acid bases, MgSO4·7H2O, MnSO4·4H2O, KH2PO4, K2HPO4, CH3COONa, fourteen amino acids, and glucose were essential for the strain’s growth and Enterocin Y31 production. Thus, a novel simplified and defined medium (SDM) was formulated with 30 components in total. Consequently, Enterocin Y31 production yield was higher in SDM as compared to either MRS or CDM. SDM improved the Enterocin Y31 production and simplified the steps of purification (only two steps), which has broad potential applications

Survivability of probiotics in symbiotic low fat buffalo milk yogurt

In present study, symbiotic low fat buffalo milk yogurt prototypes (plain and blueberry) were developed using a commercial starter containing probiotics. Samples were analyzed for physicochemical and microbiological properties, and the survivability of probiotics during 10 weeks of storage. Gross composition results were: total solids 11.60 ± 0.58 and 17.12 ± 0.36%, ash 0.82 ± 0.06 and 0.78 ± 0.02%, protein 4.49 ± 0.31 and 4.16 ± 0.11%, fat 0.68 ± 0.03 and 0.55 ± 0.05%, carbohydrates 5.68 ± 0.18 and 11.38 ± 0.18% for plain and blueberry flavored samples, respectively. Mineral contents (mg/g) were: Calcium 1.97 ± 0.20 and 1.72 ± 0.06, magnesium 1.63 ± 0.02 and 1.69 ± 0.01, zinc 0.07 ± 0.01 and 0.07 ± 0.00, sodium 0.87 ± 0.15 and 0.94 ± 0.12 for the plain and blueberry flavored yogurt respectively. The values of pH, titratable acidity and viscosity ranged from 4.34 to 4.01 and 4.42 to 3.70, 0.96 to 1.13% and 0.94 to 1.30%, 1.40 to 1.67 and 2.15 to 1.56 Pa.s for the plain and blueberry flavored yogurts respectively. The initial population of Bifidobacterium spp. and Lactobacillus casei were above 108 CFU/g for both the plain and blueberry flavored yogurts. Lactobacillus acidophilus was viable only for the first two weeks; however, Bifidobacterium spp and L. casei remained viable (>106 CFU/g) during the storage. The results indicate that the low fat buffalo milk yogurt is a good vehicle for developing symbiotic yogurt.Key words: Buffalo milk, symbiotic yogurt, refrigerated storage, probiotic survivability, physicochemical properties

Impact of Emulsifiers Addition on the Retrogradation of Rice Gels during Low-Temperature Storage

Rice and its products are widely consumed in Asian countries; however, starch retrogradation decreases the quality and shortens the shelf-life of rice foods particularly at low temperature. In this study sucrose ester (SE), glycerol monostearate (GMS), and sodium stearoyl lactylate (SSL) were added to rice flour and corresponding rice gels. Then, gelatinization properties, retrogradation characteristics, texture, and water content of these rice gels were investigated at 4°C and −20°C storage, respectively. The results demonstrated that the rice gels with 0.2% GMS had the lowest retrogradation index (ΔHr/ΔHg) (11.84%) and hardness (1359 g) at 4°C for a 10 d period, which was significantly lower in comparison to control and the other two emulsifiers (P<0.05). Adhesiveness and water content were increased compared to the other samples. Furthermore, the retrogradation of rice gels stored at 4°C was comparatively rapid compared to gels stored at −20°C. Gel samples stored at −20°C were still acceptable for more than 15 days. Thus it was revealed that GMS has the potential to retard starch retrogradation and produce high-quality rice products in preservation

Purification and Partial Characterization of Bacteriocin Lac-B23, a Novel Bacteriocin Production by Lactobacillus plantarum J23, Isolated From Chinese Traditional Fermented Milk

The exploration and evaluation of bacteriocin-producing lactic acid bacteria (LAB) have been one of the powerful means to food preservation. A total of 300 strains were isolated from Chinese traditional fermented milk products. A bacteriocin-producing LAB, named Lactobacillus plantarum J23, was screened and identified. Bacteriocin Lac-B23 from L. plantarum J23 was purified by 80% ammonium sulfate precipitation, cation-exchange chromatography, and reverse-phase high-performance liquid chromatography. Molecular weight of bacteriocin Lac-B23 was determined to be approximately 6.73 kDa by tricine sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, and it was confirmed as a novel bacteriocin by liquid chromatography-mass spectrometry. Moreover, bacteriocin Lac-B23 showed thermal stability when heated at below 100°C for 30 min, pH stability between pH 2.0 and 12.0, and sensitivity to trypsin, proteinase K, and proteinase E. The antimicrobial activity of bacteriocin could be enhanced by addition of Fe2+, Mn2+, and ethyl alcohol, and inhibited by Cu2+, K+, Ca2+, Zn2+, Mg2+, and sodium chloride. The results suggested bacteriocin Lac-B23 to have potential application prospects in the food industry

Enhancement of Innate Immune Function in Mice by Bifidobacterium bifidum FL-228.1

In this study, eight potential functional strains were selected to interfered with RAW264.7 murine macrophages and human peripheral blood mononuclear cells (PBMCs). Then, changes in phagocytic activity of RAW264.7 cells and natural killer (NK) cell activity were detected and the screened potential probiotics were further intervened in BALB/c mice to explore their immunomodulatory efficacy in vivo. In cell experiments, the results showed that the intervention of different strains significantly increased the phagocytic activity of RAW264.7 cells (P0.05). In conclusion, Bifidobacterium bifidum FL-228.1 can improve innate immune function and have a more comprehensive effect on the immune system by regulating immune cell activity, cytokine expression and mRNA levels of immune molecules related to antimicrobial peptides

Clinical efficacy and safety analysis of aumolertinib in real-world treatment of EGFR-mutated advanced non-small-cell lung cancer

Background: This study aims to determine the efficacy and safety profile of aumolertinib in the real-word treatment setting for advanced non-small-cell lung cancer (NSCLC) patients harboring epidermal growth factor receptor (EGFR) mutations.Methods: We retrospectively analyzed the clinical data of 173 EGFR-mutated advanced NSCLC patients who received aumolertinib treatment at Henan Cancer Hospital from April 2020 to December 2022. Progression-free survival (PFS) and overall survival (OS) were evaluated using Kaplan–Meier survival curves, while a Cox regression model was used for multifactorial analysis and prognostic factor assessment.Results: Among patients administered first-line aumolertinib (n = 77), the objective remission rate (ORR) of 77.92% was observed, along with a disease control rate (DCR) of 100%. The median progression-free survival (mPFS) was 24.97 months, which did not reach the median overall survival (mOS). The patients treated with aumolertinib after progression on prior EGFR-tyrosine kinase inhibitor (TKI) therapy (n = 96) exhibited an ORR of 46.88%, a DCR of 89.58%, an mPFS of 15.17 months, and an mOS of 21.27 months. First-line treatment multivariate Cox regression analysis demonstrated a statistically significant impact of elevated creatine kinase on PFS (p = 0.016) and a similar significant influence of co-mutation on OS (p = 0.034). Furthermore, subsequent-line treatment multivariate Cox regression analysis showed a statistically significant impact of elevated creatine kinase on median PFS (p = 0.026) and a significant effect on the number of metastatic organs (p = 0.017), co-mutation (p = 0.035), and elevated creatine kinase (p = 0.014) on median OS.Conclusion: Aumolertinib has shown clinical significance and can safely be used in the real-world setting for patients with EGFR mutation-positive NSCLC

Rice Protein Extracted by Different Methods Affects Cholesterol Metabolism in Rats Due to Its Lower Digestibility

To elucidate whether the digestibility is responsible for the hypocholesterolemic action of rice protein, the effects of rice proteins extracted by alkali (RP-A) and α-amylase (RP-E) on cholesterol metabolism were investigated in 7-week-old male Wistar rats fed cholesterol-free diets for 3 weeks. The in vitro and in vivo digestibility was significantly reduced by RP-A and RP-E as compared to casein (CAS). The digestibility was lower in RP-E than that of RP-A. Compared with CAS, the significant cholesterol-lowering effects were observed in rats fed by RP-A and RP-E. Fecal excretion of bile acids was significantly stimulated by RP-E, but not by RP-A. The apparent cholesterol absorption was more effectively inhibited by RP-E than RP-A because more fecal neutral sterols were excreted in rats fed RP-E. There was a significant correlation between protein digestibility and cholesterol absorption (r = 0.8662, P < 0.01), resulting in a significant correlation between protein digestibility and plasma cholesterol level (r = 0.7357, P < 0.01) in this study. The present study demonstrates that the digestibility of rice protein affected by extraction method plays a major role in the modulation of cholesterol metabolism. Results suggest that the hypocholesterolemic action induced by rice protein with lower digestibility primarily contribute to the inhibition of cholesterol absorption

Diagnostic Accuracy of Deep Learning and Radiomics in Lung Cancer Staging: A Systematic Review and Meta-Analysis

BackgroundArtificial intelligence has far surpassed previous related technologies in image recognition and is increasingly used in medical image analysis. We aimed to explore the diagnostic accuracy of the models based on deep learning or radiomics for lung cancer staging.MethodsStudies were systematically reviewed using literature searches from PubMed, EMBASE, Web of Science, and Wanfang Database, according to PRISMA guidelines. Studies about the diagnostic accuracy of radiomics and deep learning, including the identifications of lung cancer, tumor types, malignant lung nodules and lymph node metastase, were included. After identifying the articles, the methodological quality was assessed using the QUADAS-2 checklist. We extracted the characteristic of each study; the sensitivity, specificity, and AUROC for lung cancer diagnosis were summarized for subgroup analysis.ResultsThe systematic review identified 19 eligible studies, of which 14 used radiomics models and 5 used deep learning models. The pooled AUROC of 7 studies to determine whether patients had lung cancer was 0.83 (95% CI 0.78–0.88). The pooled AUROC of 9 studies to determine whether patients had NSCLC was 0.78 (95% CI 0.73–0.83). The pooled AUROC of the 6 studies that determined patients had malignant lung nodules was 0.79 (95% CI 0.77–0.82). The pooled AUROC of the other 6 studies that determined whether patients had lymph node metastases was 0.74 (95% CI 0.66–0.82).ConclusionThe models based on deep learning or radiomics have the potential to improve diagnostic accuracy for lung cancer staging.Systematic Review Registrationhttps://inplasy.com/inplasy-2022-3-0167/, identifier: INPLASY202230167

Characteristics of Flow Development and Boiling Transitions in the Liquid Oxygen Chill-Down Process in a Straight Horizontal Exit-Contracted Pipe

Liquid oxygen chill-down in a straight horizontal pipe was studied experimentally. The effect of the entrance corner was excluded, and much denser wall temperature sensors along the pipe have been set compared to the present studies. In this way, the chill-down process, as well as the development of the flow pattern, has been drawn for every test. As a result, the mechanism of LO2 chill-down would be obtained for various pressure sections. For cases with stable pressure below 1.25 MPa, liquid rewetting in the pipe is controlled by the propagation of quenching fronts. For cases with a higher pressure, liquid rewetting in the second half of the pipe is controlled by the sudden liquid fill-in. Based on the transition points obtained, heat transfer coefficients on the Leidenfrost point and critical heat flux have been correlated for various pressure sections using new approaches. Conclusions show that the correlation equations are dependent on the chill-down mechanisms

Formation of Aldehyde and Ketone Compounds during Production and Storage of Milk Powder

Certain aldehyde and ketone compounds can be used as indicators, at a molecular level, of the oxidized flavor of milk powder instead of sensory evaluation. This study investigated the formation of aldehyde and ketone compounds as affected by the heat-related processing and storage of milk powder. The compounds were extracted by solid phase microextraction fiber and determined using gas chromatography-mass spectrometry. In the results, higher contents of hexanal, 2-heptanone, octanal and 3-octen-2-one were detected in concentrated milk and fresh milk powders than in raw milk and heated milk. The levels of these compounds increased with increasing time of storage of milk powder. Meanwhile, the DPPH radical scavenging activity decreased and peroxide value increased during the production and storage of milk powder. In addition, the pore volume distribution of milk powder particle was determined by nitrogen isotherm adsorption. The porosity of milk powder was significantly correlated to the changes of aldehyde and ketone compounds during storages periods of 3 months (r &gt; 0.689, &lt;em&gt;p &lt;/em&gt;&lt; 0.05) and 6 months (r &gt; 0.806, &lt;em&gt;p&lt;/em&gt; &lt; 0.01). Therefore attention should be paid to the detectable aldehyde and ketone molecules to control the oxidized flavor, which was influenced by pre-heating as well as concentration and drying during milk powder production